.r_full {
    position: relative;
    width: 100%;
    height: 100%;
}

.a_full {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
}

.f_full {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
}

.f-center {
    display: flex;
    align-items: center;
    justify-content: center;
}


.f-y-center {
    display: flex;
    align-items: center;
}

.f-x-center {
    display: flex;
    justify-content: center;
}
